Technical Field
The present disclosure relates to a printed circuit board and a display device including the same. More specifically, the present disclosure relates to a printed circuit board (PCB) capable of addressing electromagnetic interference (EMI) and electrostatic discharge (ESD) issues, and a display device including the same.
Description of the Related Art
Generally, a printed circuit board (PCB) supports electronic circuitry thereon that is formed by applying at least one metal layer on a thin insulation substrate and then removing parts of the metal layer. PCBs find applications in various fields. Among others, in a display device including a display panel, a PCB may be connected to the display panel to supply a signal for driving the display panel or a signal for controlling the operation of the display panel.
Recently, a PCB in a display device may include circuits having various functionalities and thus has complicated structure. Specifically, a PCB may include a driving unit such as a driving integrated circuit (IC) for supplying a signal for driving a display panel and a timing controller for controlling the timing operation of the display panel. In addition, a PCB may include a communications unit composed of various circuits for communicating with an external device depending on the application of the display device. As such, PCBs include more complicated and various circuits, the PCBs include more lines for connecting such circuits. To implement complicated circuits with many lines, PCBs have a stack structure consisting of a plurality of metal layers and insulation layers in order to include more metal layers.
As PCBs have the stack structure and accordingly include many metal layers therein, voltage and electric current flowing in the PCBs have increased. Some of the voltage and electric current in the PCBs act as noise or interference to the integrated circuits in the PCBs. That is, the residual voltage and residual current in the PCBs generate electromagnetic fields which act as noise or interference. Such electromagnetic fields may have various frequencies. Such various frequencies of the noise caused by electromagnetic fields in the PCBs may superpose or overlap with the frequencies of signals supplied to the display panel from the driving unit or the frequencies of signals transmitted/received to/from the communications unit. As a result, there is a problem in that interference takes place in the signal from the driving unit or the signal to/from the communications unit by the noise caused by electromagnetic fields in the PCBs.
To address the above-mentioned problem, what is required is a PCB capable of effectively removing residual voltage and residual current in the PCB, and a display device including the same.